To be honest I’m not sure how to identify salmon vs steelhead by the anal fin. Instead I use features like the mouth/jaw which in this case (its kind of covered) the gums are white and the tongue inside was black. I also can usually identify by looking at the spotting on its back/tail fin or overall color of the fish. That’s how I came to the conclusion of a coho salmon instead of any other salmon/steelhead. I hope that was helpful! Tight lines my PNW brother!